“David Cameron has expressed regret he was unable to do more to deal with the “huge” challenge funding social care for Britain’s ageing population.

The former prime minister – who has since become president of Alzheimer’s Research UK – said a way had to be found to meet the “catastrophic” costs of caring for people with dementia.

“There is a huge social care funding challenge we have to answer, and I accept that we’ve made some steps forward, but we didn’t solve that problem,” Mr Cameron told the Financial Times.

“Everyone knows it’s a difficult conundrum. Lots of effort has been made to try and solve it but we haven’t got there yet.”

In office Mr Cameron sought to introduce a £72,000 cap on the costs an individual would have to pay towards care home charges with the state picking up any further bills.

Ministers had hoped insurance companies would develop products that would enable people to insure themselves against their care costs up to the £72,000 limit.

However the plans were put on hold in July 2015 after insurers proved reluctant to enter the market.

“The disappointment I had was I was hoping that a combination of the cap on care costs would help to deliver an insurer’s model, where a market would grow up where everyone could insure themselves against the cost of long-term care. And we just haven’t cracked that yet,” Mr Cameron said.

“I’m not in politics any more but we’ve got to find an answer. (Given) the catastrophic cost of care that people face from dementia, and I saw this with constituents, we’ve got to find a better answer there.”